OM D Audio/Video Out of Sync

I recorded some live music Saturday and was editing yesterday. I kept noticing that the audio and video of the singer were not in sync, the audio being slightly ahead. I ended up syncing them in imovie and saw they are off consistently about 1/6 second.

I also recorded some test video with my Canon dSLR to compare and try to figure out where the problem was, and that video is pretty much dead on. I can't find much on the internet about syncing problems with the OM-D. I guess I'll send it to Olympus at some point to be checked, but was curious if anyone else has noticed this.
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